One of the most common and dangerous electrosurgical procedures is monopolar electrosurgery for removing polyps, such as colorectal polyps, with an endoscope and hot biopsy forceps. While such biopsy forceps are widely used for removing polyps that may be associated with colorectal cancer, successfully removing polyps with minimal damage to a patient's tissue requires significant training to properly inspect an ablation region for thermal damage. For example, a practitioner, such as a doctor, nurse, or other trained medical professional, typically visually inspects the ablation region for growth of a white peripheral crest to indicate a depth of the thermal effects into the tissue caused by the ablation of the polyp.
On the one hand, visually overestimating the depth of the thermal effects of the ablation may lead the practitioner to incorrectly conclude that the polyp has been completely removed by the biopsy forceps and, in turn, may fail to fully remove the polyp. On the other hand, visually underestimating the depth of the thermal effects of the ablation may cause the practitioner to inadvertently damage the patient's tissue resulting in potentially life-threatening complications. Such underestimations are further complicated by the fact that these complications may include a delayed perforation of the patient's tissue after the patient as left the practitioner and is no longer surrounded by trained medical professionals for immediate treatment.
Due to the difficulty associated with estimating the thermal effects of ablation, particularly in vivo with the patient, a variety of theoretical models and devices have been developed to aid in measuring and/or predicting the depth of ablation. For example, one theoretical model attempts to correlate duration and output power of an electrosurgical device to the patient's tissue to the depth of ablation. Another theoretical model focuses on thermal management of the biopsy forceps for limiting the effective heat field in the patient's tissue via simulated computer models. However, further development of these models and devices are, to some extent, limited by an inability to accurately and precisely compare the effectiveness of these developments.
There is a need for a test system and method of determining the thermal effects of tissue ablation on an ex vivo tissue that addresses present challenges and characteristics such as those discussed above.